Mac (Rob McElhenney) wears a Fall River Marskmen t-shirt in the “Flowers for Charlie” episode of It’s Always Sunny in Philadelphia (Season 9, Episode 8). He also wears the shirt in Season 6, Episode 4.

Mac (Rob McElhenney) wears a Detroit Express t-shirt in “The Gang Gives Frank an Intervention” episode of It’s Always Sunny in Philadelphia (Season 5, Episode 4). The Express were a professional soccer team that played in the old NASL from 1978 to 1980.